In the past, as a magnetic recording medium for audio recording, video recording, information recording and the like, a magnetic recording medium comprising a non-magnetic support having provided thereon a magnetic layer containing ferromagnetic particles such as ferromagnetic iron oxide, cobalt-containing iron oxide, chromium dioxide, ferromagnetic alloy particles and the like has been mainly used. The above-described magnetic layer has high surface electric resistivity, and therefore, it is easily charged. As a result, noise occurs upon recording and playback. In addition, dust and contaminants easily attach on the surface, which causes drop out.
In general, carbon black is dispersed in a magnetic layer in order to prevent the magnetic layer from charging. However, due to the presence of carbon black, the packing density of the ferromagnetic particles in the magnetic layer decreases. As a result, the sensitivity and outputs decrease. In addition, due to poor the dispersibility of carbon black, the surface property of the magnetic layer deteriorates.
In order to solve the above problems, it is proposed, for example, in Japanese Patent Application (OPI) NO. 55433/1980 (the term "OPI" as used herein means an "unexamined published application".) that an electroconductive layer (hereinafter referred to as an "intermediate layer") having dispersed therein carbon black be provided between a support and a magnetic layer. In accordance with the above method, the packing density of the ferromagnetic particles in a magnetic layer can be improved, but the dispersibility of the carbon black is insufficient, the surface property of the intermediate layer is poor and when a magnetic layer is provided on the intermediate layer, the electromagnetic properties such as sensitivity S/N and so on, are insufficient due to the poor surface property.